Control for auxiliary speaker in radio receiver



July 11, 1967 J. T. MOZIS 3,331,024

CONTROL FOR AUXILIARY SPEAKER IN RADIO RECEIVER Filed Feb. 4, 1964 3 .51 INVENTOR.

QZYn/Q @0 55 BY United States Patent .0

3,331,024 CONTROL FOR AUXILIARY SPEAKER IN RADIO RECEIVER John T. Mozis, Berwyn, Ill., assignor to Motorola, Inc., Franklin Park, Ill., a corporation of Illinois Filed Feb. 4, 1964, Ser. No. 342,456 5 Claims. (Cl. 325312) This invention relates to radio receivers utilizing auxiliary speakers and having a control shaft extending therefrom. A control assembly is provided which includes a variable resistor control unit mounted concentric with the control shaft. A knob is also provided mounted concentric with the control shaft and engaging a rotor on the variable resistor control unit to drive the rotor. The knob also is recessed to receive and conceal a portion of the variable resistor control unit. This provides a control assembly which may be added to an existing electronic device without detracting from its appearance and without requiring modification of the electronic device.

Certain automobile users find it desirable to mount an auxiliary speaker for their automobile radio receivers in the rear of the automobile. Other automobile users prefer only a single speaker in the front of the automobile. It is desirable from a manufacturing standpoint that the same radio receiver design be utilized for both single and auxiliary speaker operation. This is because, in addition to the increased manufacturing cost of making two different models, two different models would compound installation problems for the automobile dealer upon the sale of new automobiles. Furthermore, the owner of an automobile might wish to add an auxiliary speaker some time after initially purchasing a radio receiver having only one speaker.

A solution to the above difliculties is to provide for the addition of an auxiliary speaker and a variable resistor control therefor in all radio receivers manufactured. One method of doing this is to include a variable resistor control for the auxiliary speaker in the basic radio'receiver set sold, and merely provide electrical contacts for the addition of an auxiliary speaker. Such a design, however, adds to the cost of the basic set, forcing the consumer who does not desire an auxiliary speaker to pay for additional equipment (the variable resistor contacts) which he will not use. An alternative solution is to add'the variable resistor control at the same time the auxiliary speaker is installed. Such a procedure however, often results in complex installation problems and high installation costs. Furthermore, the added control may present an unsightly appearance after being installed.

Accordingly, it is an object of this invention to provide an improved control assembly for a radio receiver utilizing an auxiliary speaker.

Another object of the invention is to provide a radio receiver for an automobile wherein a control assembly therefor is adapted to readily incorporate a variable resistor control without changing the external appearance thereof.

Still another object of the invention is to provide a radio receiver and control assembly adapted for the addition of an auxiliary speaker and wherein the cost of the basic radio receiver unit is minimized.

A feature of the invention is the provision, in an automobile radio receiver, of a variable resistor control for an auxiliary speaker which may be externally mounted concentric with a control shaft of the radio receiver, and

the further provision of a knob concentric with the shaft for both operating and concealing the control.

Another feature of the invention is the provision of a radio receiver and control assembly including a knob concentric with a control shaft and adapted to accommodate the rotor portion of a variable resistor control for 3,331,024 Patented July 11, 1967 an auxiliary speaker to operate the same. The outward appearance of the control assembly is thereby the same, whether or not it includes the fader control, and matches corresponding knobs on the opposite side of the receiver for controlling volume and tone.

Still another feature of the invention is the provision of a control for an auxiliary speaker of a radio receiver which control includes a control bushing, a base portion and a rotor portion concentric therewith, with the control bushing and the rotor and base portions all being relatively rotatable with respect to each other.

In the drawing:

FIG. 1 is a perspective view of an escutcheon panel and the controls for an auto radio receiver incorporating the invention;

FIG. 2 is an exploded view of a control assembly constructed in accordance with the invention;

FIG. 3 is a half-section of the control assembly of FIG. 2; and.

FIG. 4 is a sectional view taken along the line 44 of FIG. 3.

In accordance with the invention, a radio receiver for use in an automobile includes a housing having a pair of control shafts extending from the front thereof. One shaft regulates the volume of the receiver and may be turned by a knob. A second knob is mounted concentric with this shaft for tone regulation. The other shaft regulates the tuner of the receiver and a mounting bushing extends about this shaft andprotrudes through an opening in the escutcheon panel. A control assembly on the radio may include a variable resistor control for an auxiliary speaker for the receiver mounted concentric with the tuner control shaft. The variable resistor control includes a control bushing which threadably mounts the control on the mounting bushing. The control further includes a base portion, and a rotor portion rotatable relative thereto. The base portion of the control is secured against rotation and a first knob concentric with the control shaft is provided for rotating the rotor portion of the control with respect to the base portion. This knob includes a recess therein for accommodating at least part of the control protruding beyond the surface of the escutcheon panel to conceal the control from view. This knob also includes a resilient bushing which extends into the control bushing andmates with the inner walls thereof to hold the knob in place and prevent vibration rattle. The turner control shaft extends through the variable resistor control and control knob and has a second control knob mounted thereon for operating the control shaft. The first and second knobs match the two knobs on the volume shaft and provide a neat appearance whether or not the rheostat is used. As a result, the same outward appearance is presented when the variable resistor control isincorporated in the assembly as is presented when the control is not provided.

, Referring now to FIG. 1, an escutcheon panel 11 is shown occupying a position on the instrument panel 12 of anautomobile. The escutcheon panel includes an opening through which the tuning dial 13 of a radio receiver is visible and also contains openings for a series of tuning pushbuttons 14. Escutcheon panel 11 is further provided with an opening for a volume control shaft regulated by knob 15 and for a tuner control shaft regulated by knob 17. A tone control knob 18 is mounted coaxial with volume control knob 15 and matching control knob 19 is provided concentric with tuning control knob 17 as will be explained in more detail subsequently, for controlling an auxiliary speaker.

Referring now to FIGS. 2 and 3, the radio receiver has a housing 21 mounted behind escutcheon panel 11 and includes a mounting bushing 23 extending therefrom through an opening 25 in escutcheon panel 11. Opening 25 may be lined with a nylon or plastic liner 26 which includes a notch 27 therein, the purpose of which will be described subsequently in connection with the variable resistor control. Other types of escutcheon panels, not necessarily utilizing plastic liners, could be used within the scope of this invention. The tuning control shaft 29 of the radio receiver extends through bushing 23 and protrudes from the front of the escutcheson panel 11..

Referring now additionally to FIG. 4, a variable resistor control 31 for an auxiliary speaker for the radio receiver includes a base portion 33. Base portion 33- carries a wire wound resistor 34 and leads 35 and 36 are connected to each end of resistor 34 for electrical connection to the electronic circuits of the receiver.- A wiper 37 is carried on a rotatable plate 38. Plate 38 is connected through a lead 39 into the circuitry of the receiver and the position of wiper 37 may be altered to vary the resistance at a key point in the circuitry of the receiver to control, for example, the volume of the auxiliary speaker, or the relative volume between the basic speaker and the auxiliary speaker. Various types of circuits for doing so will be apparent to those skilled in the art.

Plate 38 -is attached'to the rotor portion 41 of the rheostat control and accordingly, the position of wiper 37 may bevaried by rotating the rotor portion 41. Both the base portion 33 and the rotor portion 41 of control 31 are rotatably mountedon a control bushing 43. Control bushing 43 includes. a hexagonal head 45-on theend thereof and further includes a threaded portion 47 for mounting the control 31 on the radio mounting bushing 23 without rotating the base or rotor portions. Baseportion 33 of control 31 .includes a portion or projection-51: thereon which mates. with notch27 in escutcheon panel 11 when the threaded portion 47 of control bushing 43is screwed onto the mountingbushing 23. This prevents rotationof base portion 33 when rotor portion 41 is rotated. Key portion 51 also serves to carry lugs 53 to which the leads 35, 36 and 39 are secured.

A control knob 19 carries; an anti-rattle bushing 55 which is of'nylon or some other. resilient material to absorb vibrationand which-extends into bushing 43 for a resilient fit with the inner walls, thereof. Bushing 55 clears control shaft 29 to permit turning ofcontrol knob 19 with respect to-shaft 29 and vice versa. Knob 19 is provided with a recess 61therein which accommodates at least part of control 31 outwardly of the surface of escutcheon panel 11. Accordingly, the control 31. is hidden from view.- A driving connection between the rotor portion 31 ofcontrol.31 and control knob 19 is provided by means of inwardly projecting fingers 63 which matewithopenings 64 in rotor portion 41. Control shaftv29 extends pastknob 19 and contains a split 67- therein upon which tuning control knob 17 is drivingly keyed.

The foregoing described construction provides an improved radio receiver control assembly adapted for use with, or without an auxiliary speakercontrol. Control knobs 17 and 19 are used with or without the control 31 to match the corresponding knobs 15 and 18. Whencontrol 31 is included, the outward appearance is unchanged. Accordingly, the expense of the variableresistor or fader, control for the auxiliary speaker is eliminated from the basic unit and the customer pays a lower price and is not required to purchase equipment which he does not intend to utilize. The control assembly of the invention might be satisfactory for other than radio use- For example, such a control assembly might be utilized to add UHF control to a television receiver.

If the customer desires, an auxiliary speaker or if he later Wishes. to. add one on his own, the procedure is simple. Knobs 17 and 19 are removed from their po-. sitions on shaft 29 and control 31 is screwed into place by threading portion 47 of control bushing 43 on mounting bushing 23. Keyed portion or projection 51 mates with notch 27. Knobs 19 and 17 are then replaced and proper electrical connection is made through leads 35,

36 and 39 to connect the resistor 34 into the electrical circuitry of the radio. The outward appearance of the control assembly is exactly as it was without control 31 in position and it is unnecessary to remove the receiver itself, or to make any modifications underneath instrument panel 12 save for the electrical connections.

It may therefore be seen that the invention provides a radio receiver control assembly. wherein a variable resistor control, may be readily mounted concentric with a control shaft externally of the receiver. The outward appearance of the receiver remains-unchanged when the variable resistor control is added, and because such addition of the control is possible, the cost of the basic radio receiver unit is minimized.

What is claimed is:

1. A control assembly for use with wave signal apparatus having a control shaft extending therefrom, said control assembly including in combination, a variable resistor control unit for electrical connection to the wave signal apparatus and having a base portion housing the resistor and a rotor portion rotatable with respect to said base portion, means for mounting said control concentric with the control shaft, means for sustaining said base portion against rotation, :and a knob for mounting concentric with the control shaft and having a recess therein for receiving a substantial part of said control to conceal the same, said knob having means thereon engaging said rotor portion for driving the same.

2. A control assembly for use with wave signal apparatus having a controlshaft extending therefrom with a first knob fixed thereto, said control assembly including in combination, a variable resistor control for electrical connection to the wave signal apparatus and having a base portion and a rotor portion, a bushing extending through said control for mounting said control concentric with the control shaft between the wave signal apparatus .and the first knob, said base portion of said control having means thereon for sustaining said base portion against rotation, a second knob for mounting concentric with the volume control shaft between the first knob and said control, said second knob having .a recess therein for receiving asubstantial part of said control, said second knob having a resilient bushing extending therefrom into said control bushing to resiliently engage the same and maintain said second knob against vibration, said second knob having means thereon engaging saidr-otor portion for driving the same.

3. A control assembly for use in automobile radio receiver apparatus having a housing enclosing a radio receiver and a control shaft and mounting bushing extending frorrrthe housing and through a control opening in .an escutcheon panel, said control assembly including in combination, a variable resistor control for an auxiliary speaker, said control comprising a base portion and a rotor portionrotatable with respect to said base portion to provide control of the auxiliary speaker, a control bushing extending through said control and rotatable with respect thereto for threadably engaging the mounting bushing to secure said control concentric with the control shaft, means for securing said base portion against rotation, a knob having a resilient bushing therein for permitting the'control shaft to extend therethrough when mounted concentric with the control shaft to be rotatable with respect thereto, said resilient bushing being extendable into said control bushing to resiliently engage the same andmaintain said knob against vibration, and means for drivingly coupling said knob to said rotor portion of said control for rotating said rotor portion with respect .to said base portion, said knob having a recess therein for receiving atleast part of said control to conceal the same.

4. A control assembly for use with automobile radio receiver apparatus having a housing enclosing a radio receiver and a control shaft and mounting bushing extending from the housing and through a control opening in an escutcheon panel, said control assembly including in combination, a variable resistor control for an auxiliary speaker for mounting concentric with the control shaft outwardly of the surface of the escutcheon panel opposite the receiver, said control comprising a base portion and a rotor portion and a control bushing concentric with said base and rotor portions, said base portion and said rotor portion and said control bushing being relatively rotatable with respect to each other, said control bushing being threadably engageable with the mounting bushing to mount said control thereon concentrio with the control shaft, means on said base portion for engaging the escutcheon panel to secure said base portion against rotation, a first knob having a resilient bushing therein mounted concentric with the control shaft and rotatable with respect thereto, said resilient bushing ex tending through said control bushing and engageable with the inner sides thereof, and means drivingly coupling said first knob to said rotor portion of said control for rotating said rotor portion with respect to said base portion, said first knob having a recess therein for receiving at least a part of said control to conceal said rheostat control, and a second knob for mounting on the control shaft for driving the same.

5. Radio receiver apparatus for use in an automobile, including in combination, an escutcheon panel with control openings therein, a housing for enclosing the radio receiver, a mounting bushing mounting the radio receiver to one surface of the escutcheon panel and extending through one of the openings therein, a control shaft extending through said mounting bushing, a variable resistor control for an auxiliary speaker, said control comprising a base portion and a rotor portion and a control bushing all rotatable with respect to each other, said control bushing threadably engaging said mounting bushing and mounting said control concentric with said control shaft, said base portion having an extension thereon, a notch formed in said escutcheon panel and mating with said extension on said base portion to secure said base portion against rotation, a knob having an opening therein permitting said control shaft to extend therethrough, said knob being mounted concentric with said control shaft and rotatable with respect thereto, and means drivingly coupling said knob to said rotor portion of said control for rotating said rotor portion with respect to said base portion, said knob having a recess therein for receiving at least a part of said control to conceal said control.

References Cited UNITED STATES PATENTS 2,706,774 4/1955 Bowman 325496 KATHLEEN H. CLAFFY, Primary Examiner. A. H. GESS, Assistant Examiner. 

1. A CONTROL ASSEMBLY FOR USE WITH WAVE SIGNAL APPARATUS HAVING A CONTROL SHAFT EXTENDING THEREFROM, SAID CONTROL ASSEMBLY INCLUDING IN COMBINATION, A VARIABLE RESISTOR CONTROL UNIT FOR ELECTRICAL CONNECTION TO THE WAVE SIGNAL APPARATUS AND HAVING A BASE PORTION HOUSING THE RESISTOR AND A ROTOR PORTION ROTATABLE WITH RESPECT TO SAID BASE PORTION, MEANS FOR MOUNTING SAID CONTROL CON- 